I have had feedback that certain random movements I program are a bit “jumpy”. Such as my old brownian movement tutorial and I really noticed it in my last tutorial, the parallax 3d depth effect tutorial. I’ve been thinking about it and looking around at some code and now have this updated brownian movement example! Updated for as3 as well as making it less jumpy.
First I’ll explain what I’ve found to be the reason of the jumpiness. And then explain and show what can be done to make this movement be more smooth.
So to examine the old jumpy code. Jump back to the first version post here. I think my technique was well thought out here, but the application was poor. It was recalculating the velocities every single frame and then incrementing the coordinate positions by the newly calculated velocities… This is where the jumpiness comes in. Even though the random value was named velocity, it didn’t actually affect the dot’s velocity, it was just a variable that stored the random value used to move the current x/y coordinates.
To help the animation be more smooth, the velocity needs to be more smooth. The velocity, rather than calculating it fresh each frame, should be randomly modified each frame. And then the new velocity will calculate the new ‘random’ position. Another addition is to introduce another force to dampen the velocity over time, so things don’t get too crazy…
Steps:
Modify velocity randomly
With velocity and current position, calculate a new position
Dampen the velocity
Example:
Here I have a velocity for the x coordinate as well as the y. I’m also experimenting with a z velocity. This adjusts the alpha and scale for depth perception. It doesn’t actually edit the depth or layer the dot shows up on the stage however… keyword here: experimenting. 🙂
[kml_flashembed fversion=”8.0.0″ movie=”https://circlecube.com/circlecube/wp-content/uploads/sites/10/2009/02/as3random_brownian_movement.swf” targetclass=”flashmovie” publishmethod=”dynamic” width=”550″ height=”550″ wmode=”transparent”]
[/kml_flashembed]
Actionscript:
[cc lang=”actionscript”]
//number of balls
var numBalls:uint = 50;
var defaultBallSize:uint = 30;
I’ve had quite a few questions about how to make depth in flash. Earlier (like, 2 years ago) I put up an experiment file to give some interactive depth to some sketchbook sketches, see Floating Sketches. I’ve finally gotten around to translating that into as3. It’s still the same basic idea, Create layers of levels, and have each one respond to the mouse a little differently. The ‘closer’ depths will move faster while the farther away depths will be slower. A simple technique called Parallax.
Seperate the scene into layers
Place the layers in the correct depth
Make closer layers react fast and farther layers slower
[cc lang=”actionscript”]
//define number of layer.
var numLayers:uint = 15;
//number of items in a layer
var numBallsPerLayer:uint = 100;
var defaultBallSize:uint = 25;
var stageWidth3d:uint = 800;
var stageHeight3d:uint = 800;
var layers:Array = new Array();
//init
makeMatrix();
//3d created by layers and placing objects on each layer – the layer has it’s own distance, simulated by movement and alpha
function makeMatrix():void {
//walk through desired number of layers
for (var layerNum:uint=0; layerNumSource
I’ve re-purposed an old project of mine, the interactive pog portfolio viewer, to activeden. I call it the pog portfolio because each work is represented by a circle, or pog, and you play ith it in the “bay” with different interactive physics configurations. When you click a pog you can view a close up image of that item and more details. The whole file has been cleaned up (code and graphics) and documented for easy customizations.It is a small file size as well, under 36kb swf!
This is mainly an image viewer, stay tuned for any updates, like video support etc.
Works and configuration loaded in through a single xml file. Select works from the bay to view title, description image and a link (if applicable). Organize works with the tags or select all and choose the physics of the bay for interactivity control (gravity, spring, grid and friction).
It is fully customizable and fully driven by xml. The xml file contains values for configuring the swf, and also all the information about each work to be included in the portfolio.
Each work is loaded into the ‘bay’ as a round thumbnail or ‘pog’. These pogs are animated with the interaction options (gravity, friction, spring and grid). The pogs are sortable by tags (parsed in from the xml).
The whole color scheme of the image viewer is configurable, or can even be set to random! Have a different color scheme every time your image viewer loads!
Clicking a pog in the interactive bay sends that thumb to the holding area and loads the close up into the focus window for that work. It also loads the details about that work into the detail box (to the right of the focus box). Each works needs a 50×50 thumbnail and a close up (max 375px x 270px) image. Focus images are all loaded in with an informative preloader and fade is once loaded.
Site easily integrates with Google Analytics to track user interactions within this flash portfolio!
All works in the portfolio are passed in through an external xml file, here is a sample work node from xml:
[cc lang=”xml” tab_size=”2″ lines=”40″]
StomperNet now has a site map. Only it’s much bigger than just a site map, we’re calling it Stomper Universe! It contains all the pieces parts that make up StomperNet. It links to different sites, video series, tools, and more by giving a 3D interactive space to inspect the thumbnails and click through to the sites! It will help visitors navigate easily to all areas of StomperNet, whether they are new to them or old favorites.
Having things drift around or move randomly has always interested me. Having an animation that is never going to be the exact same thing is very exciting. The focus turns from key-ing exact animations to programming a feel and letting the animations take car of themselves! One type of seemingly random motion is Brownian motion. This gives the movement a random walk wandering look, it will just drift around with no real direction.
Steps
Step by step this process is very simple. In every random motion you create the random number, and apply it to the property. If you want constant random action (motion) rather than just random placement, you repeat that over and over.
Make a random number (random velocity)
Apply the random number (apply velocity to property)
Repeat (if needed)
To create a random number in actionscript, use Math.random(), which creates a random number between 0 and 1. Usually you’ll want to scale it to a range you want to use. If you want a number between 50 and 100, you’d do Math.random() * 50 + 50. *50 to scale it to 0-50, and + 50 to bring it up to 50 – 100. Also if we want to get a 100 range around 0 (-50 – 50) we would do Math.random() * 100 – 50. In the code below I’ve abstracted this to Math.random() * this.randomRange – this.randomRange/2.
Here I’ve got dots created and placed randomly, with randomly set scale and alpha. On every frame each dot has a random velocity applied to it’s x and y coordinates.
The yellow dot is the simple example (code below) and the rest are included in the complex example below.
Actionscript
Simple Example:
[cc lang=”actionscript”]
dotOne.onEnterFrame = function() {
//create a random velocity for x and y direction
vx = Math.random() * 4 – 2;
vy = Math.random() * 4 – 2;
//apply velocity to coordinates
this._x += vx;
this._y += vy;
}
[/cc]
Complex example:
[cc lang=”actionscript”]
var numDots = 25;
var randomRange = 1;
for(var i=1; i<=numDots; i++) {
//create a new dot
duplicateMovieClip(_root.dot, “dot”+i, i);
//save it’s ref path for use
theDot = _root[“dot”+i];
//give it random coordinates
theDot._y = Math.random() * Stage.height;
theDot._x = Math.random() * Stage.width;
//give each dot a distinct random range
theDot.randomRange = i/numDots;
//give each dot a random size and transparency
theDot._xscale =
theDot._yscale =
theDot._alpha = i*4;
//apply this code on the dot every frame
theDot.onEnterFrame = function() {
//create a random velocity for x and y direction within the specifically created random range for each dot
vx = Math.random() * this.randomRange – this.randomRange/2;
vy = Math.random() * this.randomRange – this.randomRange/2;
//apply velocity to coordinates
this._x += vx;
this._y += vy;
}
}
[/cc]
An interactive link list. Vertically scrolling list of links or just text. Could be used for a nav menu or a link list, or even just a scrolling list. Scroll speed calculated dynamically from mouse position to give not only scrolling control, but also speed control. Reads an external XML file containing just titles and url paths and creates this interactive click-able link list! On click the link is highlighted and on release loads the url either in a blank window or not (configurable). On rollover the list item grows with animation and is highlighted (all configurable, size speed etc). Once end of list is reached scrolling stops, another version is available with a wrap-around feature: Dynamic Scrolling Link List XML driven Auto wrapping
I have been thinking of different interactions that are possible with objects. If you’ve read this blog at all you’ll know that I’ve played with physics and gravity and throwing balls and bouncing balls and all sorts. But I hadn’t wrapped my head around an interactive spinner. I know it’d be easy to make a slider or something that would apply a spin to an object, but this just isn’t interactive enough for me.
Circle with slider to rotate and button for random spin:
This attempt at spinning is ok. I mean, it spins the object and it even glides to a stop if you press the button for a random spin… But it’s just not intuitive and not fun. But if you want this, here’s how I did it.
slider.handle.onPress = function() {
spinning = false;
//drag along the line
this.startDrag(true, slider.line._x-slider.handle._width/2, slider.line._y-slider.handle._height/2, slider.line._width-slider.handle._width/2, slider.line._y-slider.handle._height/2);
}
slider.handle.onRelease = slider.handle.onReleaseOutside = function() {
this.stopDrag();
}
_root.onEnterFrame = function() {
if (spinning) {
//apply the speed to the rotation
knob._rotation += speed;
//recalculate speed
speed = speed*drag;
//if speed gets unnoticeably tiny just set it to 0
if (Math.pow(speed, 2) < .0001) {
speed = 0;
}
}
else {
//set the rotation from the slider position
knob._rotation = slider.line._x + slider.handle._x + slider.handle._width/2;
}
//spit out feedback continuously
feedbackr.text = knob._rotation;
feedbackaccr.text = speed;
}
spinner.onRelease = function() {
//find a random speed
speed = (Math.random()* 50) – 25;
spinning = true;
}
[/cc]
I want to grab it and spin it though. I want to apply the same principles from physics, like acceleration and friction as forces to the object, so I can grab to spin and release to watch it glide gracefully to a stop. I’ve been thinking about this and how I’d have to use trigonometry and stuff to do it. One day I finally had the time and tried it out. It took me a minute but I figured out that what I needed was arctangent. So (with pointers from jbum, thanks Jim!) I came up with this:
Interactive grab-able circle to spin and twirl:
[kml_flashembed publishmethod=”dynamic” fversion=”9.0.0″ movie=”https://circlecube.com/circlecube/wp-content/uploads/sites/10/2008/03/interactivespin.swf” width=”500″ height=”300″ targetclass=”flashmovie”]
[/kml_flashembed]
This one is much more interactive and intuitive. I really think this is because there are no sliders or buttons, no controls, just an object to interact with. It’s much more like real life!
Steps:
In order to make a grab and spin object
1. You have to know where you grab. The user clicks on the shape (knob) and you must figure out what degree or rotation point they have started at. (atan2)
2. As the knob is clicked and the mouse moves (dragging), calculate new rotation by mouse position
3. When mouse is released figure out the current speed of rotation and apply it to the knob with friction, so it can be thrown and spun in that way. (Of course this is optional, if you just want to spin it when the mouse is down you’re done at step 2)
Actionscript:
[cc lang=”actionscript” tab_size=”2″ lines=”40″]
damp = .96; //friction
r = 0; //rotation
accr = 0; //speed of rotation
knob.onPress = function() {
dragging = true;
//find mouse y coordinate in relation to knob origin
a = _root._ymouse – knob._y;
//find mouse x coordinate in relation to knob origin
b = _root._xmouse – knob._x;
//using arctangent find the spot of rotation (in degrees)
oldr = Math.atan2(a,b)*180/Math.PI;
}
knob.onEnterFrame = function() {
if (dragging) {
//find mouse y coordinate in relation to knob origin
a = _root._ymouse-knob._y;
//find mouse x coordinate in relation to knob origin
b = _root._xmouse-knob._x;
//using arctangent find the spot of rotation (in degrees)
r = Math.atan2(a,b)*180/Math.PI;
//use current rotation and previous rotation
//to find acceleration
//averages the acceleration with the
//previous acceleration for smoother spins
accr = ((r – oldr) + accr)/2;
//apply the acceleration to the rotation
knob._rotation += accr;
//remember current rotation as old rotation
oldr = r;
feedbacka.text = a;
feedbackb.text = b;
}
else {
knob._rotation += accr;
//apply friction to acceleration force
//and if acceleration gets tiny, just set it to zero
if (Math.pow(accr, 2) > .0001 ) {
accr *= damp;
}
else{
accr = 0;
}
}
//spit out feedback continuosly
feedbackr.text = knob._rotation;
feedbackaccr.text = accr;
}
[/cc]
I commented the code to explain what is happening, if you need more just post a comment. Let me know if you find this useful and what you end up making with it.
Here’s a graphic of a circle of men. You may recognize the outline from any public restroom. They’re standing in a corny circle holding hands, like an all over the world theme., let’s just hope they all washed their hands…
I made the graphic a while ago, and have been wanting to interactive-ize it. I’ve really been wanting to play with elasticity, throwing things and snapping to a point… Although I’m still thinking about a version where I’d spin the objects rather than just throw them, I figured I’d put it up for any feedback that comes.
The different pieces all rotate differently and it changes if you are dragging or ‘holding’ them. Then you can press the anchor (gray) button to toggle the snap. The objects will all center around the anchor and spring into place (elasticity applied to position and rotation). And then the interactivity changes and rather than dragging and dropping them, you push and bump or throw them. It almost turns into a game…
The new splash is in effect for Mazamedia’s 5th anniversary!
I just re-vamped Mark Callahan’s splash on his Mazamedia.com
Re-vamped as in made interactive innovative and fun. I was just playing with different effects and wanted to see it in action, so I applied it to Mark’s splash intro. He liked it so much he wanted to put it live on his site. That’s cool with me, thanks Mark.
New Version – The letters are anchored to their spot, but use the mouse to push or nudge them. You can also drag them try throwing them even.
[kml_flashembed publishmethod=”dynamic” fversion=”9.0.0″ movie=”https://circlecube.com/circlecube/wp-content/uploads/sites/10/2007/08/mazasplash.swf” width=”550″ height=”275″ targetclass=”flashmovie”]
[/kml_flashembed]
Vs the old static version
[kml_flashembed publishmethod=”dynamic” fversion=”9.0.0″ movie=”https://circlecube.com/circlecube/wp-content/uploads/sites/10/2007/08/mazasplashold.swf” width=”550″ height=”275″ targetclass=”flashmovie”]
First I’ll explain what I’ve found to be the reason of the jumpiness. And then explain and show what can be done to make this movement be more smooth.
I’ve had quite a few questions about how to make depth in flash. Earlier (like, 2 years ago) I put up an experiment file to give some interactive depth to some sketchbook sketches, see 
